The invention relates to a device for controlling a throttle cross-section of at least one control orifice in a bypass line of idling control of internal combustion engine, comprising a positioning motor for moving a throttle member and a return spring element for moving the throttle member to an initial position thereof. A device of this kind is already known (German Offenlegungsschrift No. 3,234,468). It has the disadvantage that in the event of the spring element being inoperative, for example because the spring element has broken, and the positioning motor being excited, or in the event of a malfunction in the electronic control device, the control orifice is opened completely by the throttle member, and the operation of the internal combustion engine is influenced in an undesirable manner or even endangered by running at too high a speed.